. >> from nbc world headquarters in new york, this is "nbc nightly news" with brian williams. >>> good evening. i'm lester holt. sitting in tonight for brian. as president obama dangled the threat of tough o'er action against russia, the crisis in ukraine took a dangerous and deadly new turn today on the ground and in the air. as ukrainian forces in the east launch a major counter offensive against pro russian insurgents who then shot down two ukrainian helicopters. but the conflict has spread to southern ukraine. a country increasingly divided against itself, coming closer to the brink. we get more from our british partner itn. >> the term civil war should not be used lightly, but tonight, ukraine appears to be perilously close. >> the southern port city of odes odessa, a city split between those loyal to russia and those to ukraine. the two sides fought in the city center and the result was a bloodbath. more than 30 known to have died, and it is likely to have been more. unlike the east of ukraine, pro russians cannot dominate here. normal ukrainians, young women, middle aged mothers